1. Field of the Invention
The present invention relates to a method for compensating a flow rate at a neutral position of an operation lever of construction equipment, capable of optimally controlling a displacement of a hydraulic pump according to an operating amount of the operation lever when the construction equipment such as an excavator is controlled on operation thereof using the operation lever.
More specifically, the present invention is directed to a method for compensating a flow rate at a neutral position of an operation lever of construction equipment, capable of enhancing the manipulation ability by enabling an actuator to be equally driven according to an operating amount of the operation lever even when an RPM (revolutions per minute) of an engine becomes different and of reducing consumption of fuel by minimizing a displacement of a hydraulic pump when the operation lever is located at the neutral position.
2. Description of the Related Art
In general, an electrical operation lever used for construction equipment outputs a signal proportional to its operating amount by manipulation of an operator (exemplary output types of the signal may include analogue voltage, PWM (pulse width modulation), and communication signals, etc.).
In accordance with the signal inputted from the operation lever, controller outputs a controlling signal proportional to operating amounts of the operation lever and pedal to an electrical proportional valve, so that working units such as a boom, an arm, and a bucket are driven to readily perform necessary working such as excavating, loading and lifting.
In a hydraulic circuit using a plurality of hydraulic pumps, a displacement is controlled by a discharged pressure of its opposite hydraulic pump in order to efficiently use the construction equipment.
In other words, when a small load is generated from the opposite hydraulic pump, a flow rate is controlled to be much discharged, and thereby efficiency is enhanced, and simultaneously the displacement of the hydraulic pump is controlled according to a difference between a preset RPM of the engine and its current RPM, and thereby motive power of the engine is used to the maximum level.
Further, when an excessive load is generated from the working unit or the like, the discharged flow rate of the hydraulic pump is reduced, and thereby efficiency of the construction equipment is enhanced.
When the operation lever is operated, a signal from the operation lever is detected to control the discharged flow rate of the hydraulic pump, and then the displacement of the hydraulic pump is controlled according to the detected signal. Further, the discharged pressure of the hydraulic pump is detected in order to constantly maintain used motive power of the hydraulic pump, and then the displacement is controlled according to the detected pressure.
However, in order to optimally control the displacement of the hydraulic pump, various pilot signals are detected. As the displacement is controlled by the detected signals, the working units such as the boom are independently controlled. For this reason, the operator has a great difficulty in controlling the hydraulic pump in the optimal state in the working site.